Scum removes foe sewage settling



April 1, 1941.

R. E. BRIGGS Scum nmuovna FOR SEWAGE SETTLING TANKS Filed May 21, 1936 [NVENTOFP. ROBERT E. BRIGGS,

BY cm. 721%,

ATT'Y Patented Apr. 1, 1941 Robert E. Briggs, Columbus, Ohio, assignor to The J eifrey Manuiacturin tion of Ohio Company, a corpora- Application May 21, 1936, Serial No. 80,979

11 Claims.

This invention relates toa new and improved scum remover for sewage settling or sedimentation tanks.

An object of the invention is to provide a pair of coordinated conveyors both moving in the same plane, one of which is adapted to direct scum which accumulates on top' of sewage in a settling tank to the eiiiuent end thereof, and the other of which is adapted to convey "said scum to a transversely extending scum trough'a-t said eiliuent and thereby to remove the scum from the tank.

' Another object of the invention is to provide conveyor means to remove accumulating scum from the sewage settling tank and to avoid'entirely the presence of any dead spots within the tank where scum might accumulate.

Still another object of the invention is to provide a settling tank for sewage with a transversely extending scum trough and with a scum chute leading from the tank to said scum trough. Other objects of the invention will appear taken on the line 2-2 of Fig. 1 looking in the.

direction of the arrows;

Fig. 3 is an enlarged longitudinal sectional view of a pivoted flight of my invention; and

- hereinafter, the novel features and combinations Fig. 4 is a transverse elevational view of the 1 device of Fig. 3. This application comprises an improvement on my application, Serial No. 701,549 for Conveyors,

filed December 8, 1933, now Patent No. 2,160,534

granted May 30, 1939.

As seen in the drawing, I provide a settling. or sedimentationtank "I having side walls anda bottom l2. Said tank 10 is preferably made of poured concrete.

Adjacent one end of said tank I is an eilluent port l3 which leads to an eflluent trough l4. Positioned in front of said eiiluent port I 3 i a scum trough l5 which extends transversely of the settling tanklfl and entirely across the effluent end thereof. The scum trough l5 communicates with a grease well 16 which may also be of concrete, by means, of a conduit II. It will thus be understood that any scum or grease received by the scum trough l5 will flow by gravity into the grease well Is. 1

Within the settling tank It, which ispreferably of elongated construction, I provide a conveyor l8 formed by a pair of endless chains l9, l9 supported and guided by sprockets of which two pairs are seen at 20, and 2|, 2|. It Will be understood that there are also two pairs of sprockets at the influent or other end of the tank Hi to support the chain l9, l9. Said sprockets 20, 20 are mounted upon a transversely extending shaft 22 journaled in bearings carried by appropriate brackets 23, 23 from the side walls II of the tank ii). The sprockets 2|, 2| are mounted upon a shaft 24 journaled in bearings carried by brackets 25, 25 supported adjacent the bottoms of side walls II, II.

The shaft 22 also carries a sprocket 26 which is connected to another sprocket 21 by chain 28,v

said sprocket 21 driving the shaft 29, which carries a gear 30. The gear 30 intermeshes with a gear 3| of the same size to which'is connected a sprocket 32, by means of shaft 33. 32 is interconnected with a drive sprocket 34 by a chain 35, said drive sprocket-34 being attached to a shaft 330i a second conveyor mechanism 31. Said second conveyor mechanism 31 comprises shafts 36 and 38, the former of which carries a pair of sprockets 39, 39, and the latter of which carries a pair of sprockets 40, 40. A

' journal bearings carried by a-bracket on top of one of the side walls II. It will thus be seen that the two conveyors l8 and 31 will be interconnected so that they both move in unison. It

may also be mentioned that these'two conveyors are driven at the same speed.

To drive said conveyors I8 and 31 a well-knownform of drive means, shown in detail in my above mentioned application, will be provided adjacent the influent end of theitank Ill and drive the conveyor l8 directly. Conveyor 31 will there-' forebe driven from conveyor I8 by virtue of the interconnection above described. In thedriving' of the conveyors their directions of travel will be as indicated by the arrows 41 and 41'.

In addition to the elements previously described, the conveyor I8 is provided with a plurality of transversely extending flights 48, and

Sprocket the conveyor 31 is provided with a plurality of transversely extending flights 43. The flights 43 and. 49 are so arranged on the conveyors II and 31 that they do not strike each other, yet travent end of'the tank 10..

Attention is directed particularly to Figs. 1, 3 and '4 of the drawing and to the construction of the flights 49 and the supports therefor.

Each of said flights 43 comprisesa channel member ill havinga length substantially equal to the width of the tank Ill, and having near each end a supporting bracket which is pivoted by a bolt 52 to a special link 53 of a chain 4|. Said link 53 is formed by a pair of side straps each having a laterally extending wing 54 adapted to ride on a guiding and supporting rail it formed by a pair of longitudinally extending angle members 56 which are supported by hangers 51 from transversely extending I-beams 3. There will, of course, be two rails 55, one for each chain 4 I.

one a certain common area adjacent the emu- At the end adjacent the hereinafter described chute 60. the rails 55 have retaining flanges 59 carried by the angle members 56 to insure contact between the pivoted flights 49 and said chute 60.

Also cooperating with the flights 49 of conveyor 31 is a sloping chute lili which extends substantially entirely across the effluent end of the tank in and has one end leading to the scum trough l5 and above the normal level of the sewage in the tank ll, as'indicated by the dotted line 6|, with the other end thereof below the normal sewage level. The lower or free end of the chute 60 is preferably tapered downwardly, to form a depending straight edged transverse lip, as seen at 62, to direct any floating material, such as scum or grease. onto the chute 60 as influenced by the flights conveyor 31.

It may also be noted that the chute 33 is attached to side walls II, it by vertical plates 63, 63.

In addition, the scum trough II has adjacent the top edge thereof a transversely extending metal wiper 65 adapted to contact the forward surface of the flights 49 and to scrape them clean of any adhering material which will then drop into said scum trough li..

It will be evident that adjacent the upper run of the conveyor 31 the flights 43 will lie flat on the chains 4i, as seen in Fig. 1. To prevent the flights 49 suddenly pivoting and splashing into the liquid as they round the sprockets 33, I provide a pair of spaced guiding cams 66 carried on a transversely extending I-beam 61 which insure a gradual swinging of said flights 43 from a horizontal position to a vertical position, which latter position they assume when traveling along the lower run of the conveyor 31.

In the operation of the device, sewage will be introduced into the settling tank I! at the influent end remote from the end illustrated in the drawing. The sewage will be allowed to settle in said tank with the organic matter settling to the bottom l2, and the liquid sewage passing through the eiiluent port l3 and the effluent trough l4. After the sewage has been allowed to settle for an appreciable time the conveyors i8 and 31 will be driven, thedrive being directly upon the conveyor l8, and thence to the conveyor 31 through the interconnecting mechanism illustrated in the drawing. Conveyors l3 and 31 will be driven in the direction of the arrows 41 and 41, respectively. Due to the construc- 49 of the tion and arrangement of said conveyors l3 and 31, as well illustrated in the drawing, the material which settles on the bottom of the tank ilwill be conveyed forwardly toward the influent end "thereof where it will be discharged into a sump under the action of the lower run of conveyor II. The upper run of conveyor II will perform a skimming operation upon the scum or floating matter, which will be largely grease which accumulates on top of the sewage in the tank l0, substantially along the line 6|. This scum will beskimmed to the rear or emuent end of said tank 10 by flights 43.

Due to the overlapping relation of conveyor 31 with conveyor IS, the flights 43 of said conveyor 31 will continue the skimming operation after flights 43 of conveyor1l8 have submerged below the surface of the sewage. Said conveyor 31 will then convey or skim the scum or floating material up the inclined chute and into the transversely extending scum trough I8, from which it will flow by gravity through the lateral conduit l1 and into the grease well 13. It will be obvious that due to the-overlapping relation of the conveyors l3 and 31, which is permitted by virtue of the fact that their movements are in the same plane, there will be a complete absence of stagnant or "dead spots" on the sewage surface. As

a consequence, the surface of the sewage will be entirely free of scum or floating matter.

It is to be particularly noted, that as the flights 43 reach the scum trough Ii they are wiped clean of any adhering matter by the wiper 35, which insures a complete cleaning of said flights. Also, as the flights 43 are swung into the liquid in tank I! they are lowered easily by earns 66 to preventan undesirable splashing of the liquid.

After the settled material and the scum have been removed as aforesaid, the conveyors l3 and 31 will be allowed to remain in a non-operating condition for another extended period of time during which settling or sedimentation of the sewage is again allowed to take place, after which the above cycle of operation willbe repeated.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In sedimentation apparatus, the combination with a settling tank, of a scumtrough extending across one end portion of said tank, a

sloping ramp leadingto said trough from a position below the normal level of the liquid in the tank, the receiving edge of the ramp being submerged in the liquid, a chain flight conveyor having a scum removing run movable along the level of the liquid in the tank to transfer floatingmaterial therefrom to said trough, mechanism comprising two pairs of spaced-apart rails for supporting the chain flight conveyor scum-removing run in predetermined position relative to such liquid level, and stationary abutments parallel to said ramp and spaced therefrom one above each of said rails to prevent upward movement of the scum removing run when traveling along'said ramp to said scum trough.

2. In sedimentation apparatus, thecombination with a tank, of a scum trough, means comprising a skimming conveyor adapted to skim the surface of the liquid in the. tank to move floating material into said trough and then move along a path above said trough, and a scraper at that edge of the trough remote from the receiving edge and at a high level relative to the latter in position to be wiped by the upwardly moving flight to dislodge adhering said trough.

3. In sedimentation apparatus, the combination with a tank, of a scum trough having a receiving edge at a relatively low level and the opposite edge at a relatively high level, means comprising a conveyor having a pivoted flight for material from the latter into transferring floating material from the tank over the lower edge of the trough intov thelatter, and a scraper at the higher edge of thetrough in position to wipe adhering material from the flight into said trough as the flight passes by.

4. In sedimentation apparatus, the combination with a settling tank, of a scum trough, a chain conveyor comprising pivoted flights, means comprising supporting sprockets rotatable on horizontal axes for guiding the chain conveyor for movement of the flights along the surface 01 the liquid in the tank to transfer floating material to said trough and for subsequent movement of the flights upwardly along a\path above I said trough, and a scraper mounted in elevated position relative to the receiving edge of the trough and spaced therefrom in position to be wiped by the pivoted therefrom of adhering 5. In sedimentation apparatus, the combina tion with a tank, of a scum trough having one wall with its upper edge at a relatively low level and its opposite wall with its upper edge at' a relatively high level a scraper at said upper flights to effect removal material into said trough.

edge conveyor mechanism comprising a flight,

and means for guiding said conveyor mechanism to cause said flight to transfer floating material from the surface of the liquid in the tank'to said trough and then move said flight upwart il past said scraper at said higher edge of theltr ugh along a path to cause the flight to wi e said scraper to dislodge adhering material from the flight into said trough. g I

6. In sedimentation apparatus, the co bination with a sedimentation tank, of a scum freely swingable surface of the liquid in the tank to convey floating material, and curved cam mechanism in position to be engaged by the flight while moving along such curved path to 'efiect gradual svflngnism spaced from one said flexible draft mechanism to cause said flight to enter the liquid gradually.

supporting the flight in parallelism with the flexible draft mechanism,

end of said orbital path mechanism in position for engagement by said flight to effect gradual swinging of the flight to its suspended vertical position and gradual entry of the flightinto the liquid at the beginning of its scum removing run.

9. In sedimentation apparatus, the combination with a tank, of a conveyor comprising flexible draft mechanism with a flight pivoted thereto for movement downward to skimming position at the surface of the liquid in the tank, and spaced-apart cams mounted adjacent the beginning of the skimming run in position to be engaged by the end portions of said flight to eifect gradual swinging of the latter as it moves downwardly to said-surface and thereby effect gradual entry of the flight into'the liquid with minimum disturbance thereof.

of travel of said draft 1. 10. In sedimentation apparatus, the combinamerged in the liquid, a ..chain flight conveyor having a scum removing run movable along the floating material therefrom to said tron comprising spaced-apart rails for said scum trough. I

11. In sedimentation apparatus, the combination with a tank, of flight conveyor mechanism mountedthereon to extend thereacross and comprising flexible draft means, means guiding said draft means around a'flxed axis, a flight pivoted surface and into upright position for conveying travel along the d ROBERT E. Barons.

and curved cam mechagh, mechanism 

